If you like to know, just start with the definition of Scrum:

A scrum (short for scrummage) is a method of restarting play in rugby football.

— http://en.wikipedia.org/wiki/Scrum_(rugby)

This is how Scrum looks alike. Picture is called "Frascati Rugby" by f/orme taken from Flikr is licensed under CC BY 2.0

And that is what is all about. If you are able to quickly restart the product development game at anytime with all your team members - then you are doing a scrummage. Anytime in rugby means:

Scrum is utilised either after an accidental infringement or when the ball has gone out of play.

— http://en.wikipedia.org/wiki/Scrum_(rugby)

Feeling Scrum

In product development there is usually a lot of accidental stuff going on and sometimes even combined with "ball has gone out of play". But that's also the place where the magic happens. I've seen it last time with my new team: It was Monday, the day before delivery and we had still two stories to close. We were getting a little bit uneasy because we found some bugs and learnings to improve the product. So we needed to decide whether or not to include the learnings this sprint or postpone them. Furthermore we needed to pit against the open tasks and bugs. So we needed to get the ball back in the game and it felt like Scrum: Side by side, depending on each other, talking, shouting, passing the ball, passing the lead - and then we finally scored. There was trouble, yes - but also a lot of energy. Simply put: Feeling good and proud about what and how we accomplished it.